1. Field of the Invention
This invention relates to transdermal patch for delivery of a nonsteroidal antiinflammatory drug, which is used in inflammatory diseases such as deformative arthritis, articulatio humeri periphery inflammation, myalgia, contusion, sprain, backache, and so on.
2. Description of the Prior Art
Nonsteroidal antiinflammatory drugs have powerful antiinflammatory action and alleviat pain. Lately, in the orthopaedic surgery field, they are representative drugs for treating deformative arthritis, articulatio humeri periphery inflammation, tendinitis, tendosynovitis, peritendinitis, myalgia and the like. However, when they are taken orally as a tablet or capsule, or injected into the muscles, they can cause digestive trouble, liver trouble or systemic adverse effects because they are absorbed through the gastrointestinal tract. Therefore, to mitigate these adverse effects, in the case where they do not need to be administered to the whole body because the inflammed part is local and occurs relatively near to the body the surface, local agents, for example, the external patches such as a poultice or plaster, or the dermal absorption agents such as ointment, cream or gel have been developed and are used, of which most drug components act only in a limited way on the affected part and its surroundings to give a local effect.
Among these dermal absorption agents, ointments are applied easily even in active parts such as arthritis but the administration amount is not exact, the drug effect is not continued, and the drug effect may be reduced by the loss of drug due to contact with the patient""s clothes or the other irritation during the administration. The patches have a problem in maintaining their adhesion to the skin but, compared to the ointment, the administration amount is exact, the drug effect lasts and the control of the drug administration is easy. For the reason of the pharmaceutical preparation""s property, patches, relative to ointments, are used more in shoulder pain, neuralgia, arthralgia, backache and the like. As representative examples, there are the patches of nonsteroidal antiinflammatory drugs such as ketoprofen, indomethacin, flurbirprofen, piroxicam, ferbinac and the like.
A basic consideration points in developing these antiinflammatory drugs, first of all, the drug should be released continuously, and then the released drug should rapidly penetrate the corneum to be absorbed into the affected tissue, the corneum being a powerful obstacle for skin permeation, and the patch components should not adversely effect the skin as to skin irritation, and the like, in adbering the patches to the skin. Various methods of making these patches for antiinflammatory drug have been developed, for example, the drug solubility in a base was increased to accelerate the drug movement as described in Japanese Patent Laid-Open No. sho 63-88125 or sho 57-140711; the drug release in the base was increased as described in Japanese Patent Laid-Open No. Pyong 6-247856 or pyong 4-173731; a drug in the base was made nearly in the state of saturated solubility in order to accelerate the drug release into the corneum from the base as shown in Japanese Patent Laid-Open No. sho 60-185713; an absorption agent befacient was used to promote the dermal absorption of the drug component as described in Japanese Patent Laid-Open No. sho 57-75918 or 56-169623; and others such as the water retention of the base was increased to hydrate or soften the stratum corneum or the adhesion to the skin is raised to accelerate the dermal absorption.
However, in the case where the patch including a nonsteroidal antiinflammatory drug is manufactured according to the proposed methods as above, for instance, that it is mixed in a base including a large quantity of moisture like a poultice, since most of drugs are insoluble in water to be deposited in the base, the drugs"" movements are restrained and the delay of the drug release hinders the rapid effect of the drug. Also, in attaching it to the skin, the pharmaceutical preparation is not completely in contact with the skin, whereby a sufficient quantity of drug is not transported to the skin, as a result, the drug action may be lowered. In addition, they are troublesome to use and not economical such that the separate patch supplementary member like an adherent cloth should be used to fix the pharmaceutical preparation to the skin. Besides, when it is mixed in an oil-soluble adherent base such as a plaster, it can raise the drug solubility in the base but gradually the drug is precipitated, and because of the strong skin-adhesion, the adverse effect such as itching or erythema can easyly appear. Also, when the pharmaceutical preparation is removed from the skin, the pain due to the physical irritation or the damage to the corneum may be occur. In the summer season or when sweating, due to the skin secretion, the patch is easily falls off the skin. Thus, a new pharmaceutical preparation is to solve the above problems is needed.
This invention is designed to solve the problems as above, the object of the invention is to provide a dermal absorption type patch with the drug component being a nonsteroidal antiinflammatory drug which is excellent in being released from the base and absorbed through the skin and which provides good skin adhesion, without skin irritation and is pharmaceutically stable.